1 files changed, 138 insertions, 0 deletions
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..d66f483
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,138 @@
+// WTFPL
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <sys/time.h>
+#include <sys/mman.h>
+#include <sys/param.h>
+
+#define MS  * 1000
+#define SEC * 1000000
+
+#define DEBOUNCE (10 MS)
+#define THREAD_WAIT (100 MS)
+#define BACKLIGHT_TIME (10 SEC)
+#define BACKLIGHT_FADE_FRAMETIME (50 MS)
+#define BACKLIGHT_FADE_TIME (1000 MS)
+#define BACKLIGHT_FADE_STEPS (BACKLIGHT_FADE_TIME / BACKLIGHT_FADE_FRAMETIME)
+
+#define KEYPRESS_SIZE 72
+#define KEYBOARD_FILE "/dev/input/event1"
+#define BACKLIGHT_FILE "/sys/class/leds/keyboard_light/brightness"
+
+//#define BACKLIGHT_FILE stdout
+
+#define MAX_BRIGHTNESS 255
+
+static struct timeval* last_press;
+static uint32_t curr_brightness;
+static FILE* backlight_fp;
+
+void write_to_backlight(int n) {
+	fprintf(backlight_fp, "%d", n);
+	fflush(backlight_fp);
+
+	curr_brightness = n;
+}
+
+#if 0
+void backlight_fade(void) {
+	short brightness_step = MAX_BRIGHTNESS / BACKLIGHT_FADE_STEPS;
+	short* brightness = malloc(sizeof(short));
+
+	*brightness = MAX_BRIGHTNESS;
+
+	fprintf(stderr, "ha, gay\n");
+
+	do {
+		fprintf(stderr, "%d %d %d\n", *brightness, brightness_step, 0);
+
+		write_to_backlight(*brightness);
+		*brightness -= brightness_step;
+
+		usleep(BACKLIGHT_FADE_FRAMETIME);
+	} while (*brightness >= brightness_step);
+}
+#endif
+
+void backlight_off(void) {
+	if (curr_brightness == 0) return;
+	write_to_backlight(0);
+
+//	backlight_fade();
+}
+
+void backlight_on(void) {
+	curr_brightness = MAX_BRIGHTNESS;
+
+	write_to_backlight(MAX_BRIGHTNESS);
+	usleep(BACKLIGHT_TIME);
+}
+
+void light_thread(void) {
+	// check last_press vs time, do the thing
+	backlight_fp = fopen(BACKLIGHT_FILE, "w");
+
+//	FILE* backlight_fp = BACKLIGHT_FILE;
+
+	struct timeval now;
+
+	uint64_t now_usec;
+	uint64_t press_usec;
+	uint64_t diff;
+
+	while (1) {
+		gettimeofday(&now, NULL);
+
+		now_usec = now.tv_sec * 1000000L;
+		now_usec += now.tv_usec;
+
+		press_usec = last_press->tv_sec * 1000000L;
+		press_usec += last_press->tv_usec;
+
+		diff = now_usec - press_usec;
+
+		if (diff > BACKLIGHT_TIME)	backlight_off();
+		else						backlight_on();
+
+		usleep(THREAD_WAIT);
+
+		fflush(stdout);
+	}
+}
+
+void on_press(void) {
+	gettimeofday(last_press, NULL);
+}
+
+void daemonize(void) {
+	daemon(0, 0);
+}
+
+int main(int argc, const char* argv[]) {
+	FILE* fp = fopen(KEYBOARD_FILE, "r");
+	fseek(fp, 0, SEEK_END);
+
+	void* discard = malloc(KEYPRESS_SIZE);
+
+	// shared mem b/c new proc doesn't share mem space
+	last_press = mmap(NULL, sizeof(last_press), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+
+	if (fork() == 0) {
+		daemonize();
+		light_thread();
+	} else daemonize();
+
+	while (1) {
+		fseek(fp, 0, SEEK_END);
+		fread(discard, 1, KEYPRESS_SIZE, fp);
+
+		on_press();
+
+		usleep(DEBOUNCE);
+	}
+
+	return 0;
+}